When the pursuit of mastery goes bad

At what point does passion (typically seen as a “good” thing) become obsession (typically regarded as a “bad” thing)? At what point does the achievement of mastery lose its value because you’ve “cheated” to get there? And why are some things considered cheating (for instance, performance enhancing drugs) and some are not (for instance, performance enhancing equipment)?

Unfortunately, I don’t have any answers to share, at least not yet. I’ve thought about the question of doping in a generic sense, such as when Major League Baseball was called before the US Congress to address steroid use, but I’ve not given it a whole of thought in terms of the pursuit of mastery.

Having said that, though, it seems to me that the use of performance enhancing drugs is more about achieving specific, short term goals than about achieving long term mastery of an activity. In its own way, this is just another battlefront in the ongoing war against mastery.